I wrote an article for this Sunday’s New York Times Magazine about the grey zone between coma and consciousness. Stories like this one are always hard, because there are so many crucial dimensions to the subject and so little room to do justice to them all. For example, I couldn’t even begin to explain how the research I describe in the article–using PET and MRI scans to measure the brain activity in people with traumatic brain injuries–is a beautiful reverse twist on some of the most famous research ever done on the brain: the nineteenth century doctor Pierre Paul Broca’s discovery of a region of the brain dedicated to speech.

In 1861 Broca (1824-1880) treated a man who had suffered